Question

Choose three analogous organs that are found in both mammals, squid, and earthworms. Compare and contrast their structure and function.

Answer 1

Analogous organs are defined as the organs of different animals that are having different structure but perform the same functions.  

Mammals	Squids	Earthworm
1.Stomach Structure: The stomach in mammals is transversely arranged and in most forms they take a saclike form. It is divided into two regions, namely cardiac and pyloric. The cardiac part is adjacent to the oesophagus and secretes mucus. The posterior part of the stomach leading into small intestine, called pyloric region. Function : digestive function The stomach serves as a temporaryreceptacle for storage and mechanical distribution of food before it is passed into the intestine.	1.Stomach Structure: stomach is a small, shiny white sac that connects to the stomach pouch or caecum. Function: digestive function Digestion of food begins in the stomach. The caecum also performs some digestion and is the primary site of absorption of nutrients. Enzymes from the liver and pancreas help digestion.	1.crop structure: it is closer to the head.bulge of the esophagus of an earthworm. Function: digestive function Food passes from the esophagus to the crop, which is a temporary food storage area. In the crop the food gets  is mixed together.This mixture then moves into the gizzard.
2.Kidney structure: Each kidney is comprised of a fibrous outer layer called the renal capsule, a peripheral layer called the cortex, and an inner layer called the medulla.The renal pelvis then transmits the urine to the bladder via the ureter. Function: excretory function They help the body pass waste as urine.	2.kidney Structure: it is a slightly larger organ is located in the same location as the systematic heart and may be covering the heart. Function: excretory function it is used to remove waste products from the blood.	2. Nephridia structure:It has an elaborate system of excretion, which consists of small, coiled tubes with walls that are glandular and richly supplied with blood vessels. These coiled tubular excretory structures are known as nephridia and these are analogous to kidney. Function: excretory function it performs a function similar to thevertebrate kidney. Nephridia remove metabolic wastes from an animal's body.
3.Lungs Structure:The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles). Function: respiratory function The main function of the lungs is the process of gas exchange called respiration (or breathing). In respiration, oxygen from incoming air enters the blood, and carbon dioxide, a waste gas from the metabolism, leaves the blood.	3.Gills Structure: they are the two white,feathery structures located on each side of the mantle cavity. Function: respiratory function gills are used to breathe, they extract oxygen from the water.	3.Skin Structure: It is covered by a thin cuticle that is secreted by the underlying epidermis. The circular and longitudinal muscles that power locomotion and movement lie just under the epidermis. Function:They breathe through their skin. Oxygen and carbon dioxide pass through the earthworm’s skin by diffusion. For diffusion to occur, the earthworm’s skin must be kept moist.,